How can I remove a threaded allen screw?

Question

I have a screw stuck in something, it's an allen screw, is there a way I can get it out?

Thanks,

Jay

The screw is stuck in, there is no grip left on the screw for the allen key. So a allen key won't work.

Answer 1

One little dodge that I have used using a hard masonry nail if its a small screw, it has to be small enough to go into the hexagon (otherwise it may spread the screw then it will never come out) It has to be hard as well then tap quite hard but not like an idiot the nail and this will just sink the screw into the shaft or what ever it is locking on to There is always some tolerance on threads no mater how little it just takes the bite off the screw end, also the shock helps and if you can get any bite with with an Allen key it might just free. Also just remember that we have both metric and imperial size keys and some are just a touch larger than the other set.

Answer 2

First of all I agree with a number of the ideas presented below but the one that should work in all cases is to utilize a small screw extractor, which requires you to drill the proper sized hole in the allen screw.

Purely drilling out the allen screw would require you to use a drill bit that is likely going to damage the threads on what ever the allen screw is screwed into. With the screw extractor you can use a drill bit that is small enough it should not damage the threads.

It is also possible that a larger screw extractor may actually catch on to whatever is left of the allen head and back it out without having to drill a hole.

The idea about using the saw to cut a groove so you could use a screwdriver is also novel. It is possible that even if the allen head is flush with whatever it is screwed into a groove could be cut using a high speed rotary tool and the proper bit. A pointed diamond bit might do the job. The screw extractor would be easier however.

Answer 3

It depends on how big the screw is, what it is screwed into and what type of Allen screw but I would suggest the following

An impact driver should loosen it if the head is not too damaged

"Bolt headed" screw you could try sawing part way through the head to form a slot for a flat bladed screwdriver.

"Molegrips" might get enough of a grip to turn it

A hammer and sharp pointed drift, hit the head off centre to turn it.

If all else fails a drill and easiouts should get it, just remember to drill deep enough but leave enough material around the sides to give the easiout something to grip

If you still cant get it then drill a hole a faction smaller than the core diameter and remove what's left of the threads with a scriber. You can find drill size from a chart on web (just google it)

A squirt of WD40 would help which ever method you try

Answer 4

There is a tool available - thread (or tap) extractors, like a small fluted and tapered rod. They work by gripping the screw from a holr drrilled on the inside. You drill a small hole down centre of screw, then insert the extractor and lightly tap - the tool has spiral flutes which grip the screw and a square head to use as you would a bolt head (i.e. undo it with a spanner or tap-wrench). As the spiral on the flute is anti-clockwise, the screw can be removed by carefully unscrewing, because as you turn the extractor anti-clockwise - it unscrews the damaged screw.
In extereme cases - it is possible to drill down the whole length of the allen screw, and re-thread using a 'tap' (i.e. thread cutting tool) - to do this you MUST know what thread it is, and you MUST know the root size of the thread. - - - **** If you do not understand root sizes, do not attempt this -----ask a toolmaker, or other machinist for help. Good luck with the extractor method.

Answer 5

1) if accessible cut a slot across the head and use a screw driver
2) buy a set of screw extractors( they are tapered with a left hand thread) drill a hole down through the allen screw and 'screw' in the extractor in the 'unscrewing' direction. When the extractor is tight it will start to unscrew the allen screw.
3) if all fails, drill out the screw and re-tap the thread.

Answer 6

Presuming the "socket" part of the screw is damaged (why ask the question otherwise?), is it possible to get a hacksaw to the head of the allen screw and saw yourself a slot for a normal slotted screwdriver?

Soak the screw in penetrating oil such as WD40. Squirt it regularly for a day or two. Get the "next size up" allen key and try to hammer it into the head of the screw and gently, but firmly, try to unscrew it.

If none of this advice works, seek a local engineering workshop to sort this out for you. It should be quite inexpensive...

Answer 7

The thing with an allen screws is that they are hardened steel, so, to drill it out you will need a tungsten tipped drill the size of the allen screw, you will have to sharpen the drill, if you have a green `stone` all the better, then drill it out, (mind it doesn`t wander off), keeping the drill bit sharp, and then re-tap the hole, .

Answer 8

Put some superglue into the top of the screw and stick allen key into it. When the glue is dry you should be able to turn the allen key and screw together to undo it.

Answer 9

First spray the screw with a good moly type penetrant, let it soak in. Take a thin blade hardened screwdriver and bang a notch in the lip of the screw, then tap the screw at a 30 degree counterclockwise angle. Works about half the time.

Answer 10

Screw extractors are basically reverse drill bits. They are available at hardware stores and are relatively easy to use. If you can determine the size of the screw, you can buy the closest sized extractor available. It will bore into the broken screw and then, while reversing the drill direction, it will pull out the problem.